1. Field of the Invention
The present invention relates to a cap moving mechanism, a liquid ejecting apparatus and a liquid ejection characteristics maintaining mechanism therefor. More particularly, the present invention relates to a cap moving mechanism, a liquid ejecting apparatus and an ejection characteristics maintaining mechanism to move a cap for sealing a liquid ejecting head for ejecting liquid to a target.
2. Description of the Related Art
As an example of a liquid ejecting apparatus, an inkjet type recording apparatus performs recording on a medium to be recorded by ejecting ink from a discharge opening provided at a recording head. The inkjet type recording apparatus includes a cap for sealing a surface on which the discharge opening is formed in case of the cessation of recording, and prevents the discharge opening from drying. The cap holds the ink compulsorily discharged from the discharge opening during cleaning the discharge opening. As an example of a cap moving or capping mechanism to move such a cap for sealing the recording head, there is a method of moving the cap up and down in a direction perpendicular to the recording head by rotating a shaft including a cam directly under the cap as disclosed, for example, in Japanese Patent Application Publication (Laid Open) No. 2002-307700.
In the conventional capping mechanism as described above, however, it is necessary to generate a time lag so as not to transmit the driving force of a motor to the cap during a predetermined time period in order to use various kinds of operations such as moving the cap, feeding the medium to be recorded or the like. As a means for generating the time lag, there is a method of providing means for engaging a claw on the way for a transmission mechanism (or gear) to transmit the power of the motor. In case of the method of providing a claw, however, since the mechanism moving the cap receives the push-up load of the cap when the cap is separated from the recording head and lowered, the cap could not be moved smoothly. In addition, in the method of moving the cap using a gear and a cam, it was difficult to generate the time lag. Further, there occurs a tooth skipping sound where the gear does not rotate against the driving force after the cap has been completely raised or lowered.
Meanwhile, in order to avoid providing the time lag as mentioned above, there is a method of providing a motor for moving the cap and a motor for feeding the medium to be recorded respectively. In this case, however, there is a problem that the number of the parts is increased.